Several meta-analyses over the last 10 years have found a benefit to using dexamethasone as an adjunct for reduced recurrence of migraine (for example, BMJ in 2008 and European Journal of Neurology in 2013). Pooled data estimate a number needed to treat (NNT) of 9. The suspected mechanism is that it works by dampening the state of cerebral neurogenic inflammation. The current study looked to see whether a longer-acting steroid would achieve a better response over the 7 days post-ED presentation.

Annals of Emergency Medicine, November 2018